As a lifelong book lover, I’ve been known to rack up quite the bookstore bill, and often find self-control difficult to exercise when I’m lost in the stacks. Unique copies of my favorite books, such as a holographic edition of Haruki Murakami’s A Wild Sheep Chase and a signed copy of the illustrated Harry Potter and the Chamber of Secrets, are among my most prized possessions. However, there are some limits to how much I’m willing to spend on books, and these rare reads—cashing in as some of the most expensive titles in the world—definitely make the cut!

The Tales of Beedle the Bard (“The Moonstone Edition”), J.K. Rowling: $3.98 million

Arguably, you can’t put a price tag on the magic of the Harry Potter series. However, two copies of this handwritten and illustrated companion collection have sold for upwards of 4 million (muggle) dollars!

The Birds of America, John James Audubon: $10 million

Only 120 copies of this hand-colored, life-sized book were ever completed by the renowned artist, so its frequent moniker as “the most expensive book in the world” comes as no surprise.

Codex Hammer, Leonardo da Vinci: $30.8 million

Microsoft’s Bill Gates took this rare notebook (full of over 300 original notes and illustrations) off the market in 1994, though he has been lending it to museums once a year ever since.

Though I think I’ll remain loyal to the discount tables at my favorite bookshops until I strike the lottery, it sure is fun to dream!